WASHINGTON -- Sen. Richard Lugar (R-Ind.) and his wife have been ruled ineligible to vote at the Indiana address they have used for decades because they moved to Virginia decades ago.

The Marion County Election Board voted along party lines, with the two Democrats siding against Lugar and the one Republican favoring the senator's case.

The ruling adds fuel to the charges of his Republican primary opponent, state Treasurer Richard Mourdock, that Lugar is not really a Hoosier anymore.

It's also the first time a decision on the issue of his residency has gone against Lugar. The state attorney general and the state election board previously found he was eligible to be on the Indiana ballot even though he lives in Virginia.

Lugar campaign spokesman Andy Fisher cast the county board's decision as purely partisan and accused Democrats and Mourdock of wasting time and money with legal proceedings because they cannot beat the veteran lawmaker at the ballot box.

Here is Fisher's statement:

"Today, the Democrat-controlled Marion County Election Board ignored the Indiana Constitution, the express direction given to Senator Lugar by the Marion County Voter Registration Board, and the opinions of three Indiana Attorneys General -- the officials ultimately responsible for enforcing state election law -- to reach a conclusion that Senator and Mrs. Lugar have incorrectly voted in their precinct since he became a U.S. Senator.

"Since Senator Lugar took office, he and Mrs. Lugar have scrupulously complied with Indiana law, which preserves the residency of Hoosiers serving their state and country outside of Indiana. The Lugars have also sought and followed the express direction of every legitimate government authority to have addressed the question.

"It is an outrage that Indiana Democrats and Treasurer Mourdock's camp are happy to waste taxpayer money in tying up the courts. They apparently don't see any path to victory at the ballot box, so they keep maneuvering in hopes they can avoid competing head-on with Senator Lugar.

"Unfortunately, the Democrats on the County Election Board and Treasurer Mourdock's supporters are attempting to tarnish Senator Lugar and his family, and deprive them [of] their fundamental right to vote. This personal attack comes on the heels of the Indiana Election Commission's bipartisan, unanimous decision denying a similar challenge to Senator Lugar's ability to stand for re-election.

"Hoosiers everywhere have made it clear that they won't stand for these continued, calculated efforts to unfairly tarnish an Indiana statesman and his family. They agree with Senator Lugar that we should be discussing the real issues in this election: job growth, balancing the budget, national security and building a better future for Indiana and our country."

"If a person has established residency for voting purposes in an Indiana precinct prior to his or her service in Congress, that residence remains the Congressperson's residence as long as he or she remains on the business of the state or the United States. A continual physical presence is not required in order to maintain his or her residency status."

While Democrats think they can beat Mourdock in the general election, the Tea Party has been pushing him heavily in the primary, with the national Tea Party group Freedom Works addressing Lugar's residency during a conference call with reporters on Thursday morning.

Ryan Hecker, the group's chief operating officer, compared Lugar with Sen. Orrin Hatch (R-Utah), whom the group is targeting for defeat in Thursday night's Utah Republican caucuses. The comparison centered mainly on the records of the two long-term senators.

Lugar "hasn't lived in Indiana since the 1970s. He has just as bad of, if not worse, record than Orrin Hatch," Hecker said. "The Tea Party movement is strong in Indiana."

This article has been updated to include remarks made by the Tea Party group Freedom Works.